sBSpline

A new sBSpline does not output a ready-made circle: points must first be drawn. BMD describes it as sPolygon with B-Splines in place of Bézier curves: an influence point replaces the central point and handles used by Bézier.

Draw with sBSpline selected while viewing its result through sRender. Clicks add control points; closing at the first point completes the outline. The curve smooths between their influences, so the silhouette need not coincide with every marker.

The shape curve automatically receives a key when the node is added on the current frame. Editing the shape on another frame creates another key and interpolation. Set the intended frame before creating a static shape.

Outline and geometry animate differently. Length reveals an already drawn outline, while moving a control point changes the silhouette. Size and Offset transform the whole figure while preserving the meaning of its relative point arrangement.

Fill Method [3D], Z Offset [3D] and rotation fields are retained from the original Inspector. Their presence is not evidence of a scene3d port. The lessons use simple planar shapes and an explicit shape → sRender → image boundary.

The exercises provide a manual drawing recipe rather than hidden prebuilt geometry: create the control points yourself. Viewer percentages guide mouse placement; they are not native-coordinate serialization or a .comp file.